While we might consider biometrics to be just another useful application of computer vision, the concept of personal identity is important from several perspectives. From a cultural perspective, the more the world converges, the more individual cultures wish to maintain their separate identities. From an individual perspective, the greater the population and the tendency to reduce people to stereotypes, the greater the desire to establish an individual identity. There is, however, another level where identity and the verification of identity is becoming increasingly important in relation to all manner of transactions, from those related to mobility, to those related to legal, and political, rights and obligations, to those of financial and economical transactions. The intrusion of technology into these areas is not new, but their heightened visibility and ubiquity can create anxiety. This holds particularly true for biometrics.

In this work, the social problems of biometrics are addressed from a security and privacy perspective through a template protection technology called "revocable biotokens". Revocable biotokens incorporate ideas from computer vision, pattern recognition, cryptography and network security, making the approach a uniquely cross-disciplinary endeavor. When pattern recognition and cryptography are combined, a new class of algorithms and protocols enables privacy preserving identity verification, including a full "Biocryptographic Key Infrastructure" with applications to the Internet and beyond.

This work was supported by NSF STTR Award No. 0750485 and NSF PFI Award No. 0650251